/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.math;

import java.io.Serializable;

/** A point in a 2D grid, with integer x and y coordinates
 *
 * @author badlogic */
public class GridPoint2 implements Serializable {
    private static final long serialVersionUID = -4019969926331717380L;

    public int x;
    public int y;

    /** Constructs a new 2D grid point. */
    public GridPoint2 () {
    }

    /** Constructs a new 2D grid point.
     *
     * @param x X coordinate
     * @param y Y coordinate */
    public GridPoint2 (int x, int y) {
        this.x = x;
        this.y = y;
    }

    /** Copy constructor
     *
     * @param point The 2D grid point to make a copy of. */
    public GridPoint2 (GridPoint2 point) {
        this.x = point.x;
        this.y = point.y;
    }

    /** Sets the coordinates of this 2D grid point to that of another.
     *
     * @param point The 2D grid point to copy the coordinates of.
     *
     * @return this 2D grid point for chaining. */
    public GridPoint2 set (GridPoint2 point) {
        this.x = point.x;
        this.y = point.y;
        return this;
    }

    /** Sets the coordinates of this 2D grid point.
     *
     * @param x X coordinate
     * @param y Y coordinate
     *
     * @return this 2D grid point for chaining. */
    public GridPoint2 set (int x, int y) {
        this.x = x;
        this.y = y;
        return this;
    }

    /**
     * @param other The other point
     * @return the squared distance between this point and the other point.
     */
    public float dst2 (GridPoint2 other) {
        int xd = other.x - x;
        int yd = other.y - y;

        return xd * xd + yd * yd;
    }

    /**
     * @param x The x-coordinate of the other point
     * @param y The y-coordinate of the other point
     * @return the squared distance between this point and the other point.
     */
    public float dst2 (int x, int y) {
        int xd = x - this.x;
        int yd = y - this.y;

        return xd * xd + yd * yd;
    }

    /**
     * @param other The other point
     * @return the distance between this point and the other vector.
     */
    public float dst (GridPoint2 other) {
        int xd = other.x - x;
        int yd = other.y - y;

        return (float)Math.sqrt(xd * xd + yd * yd);
    }

    /**
     * @param x The x-coordinate of the other point
     * @param y The y-coordinate of the other point
     * @return the distance between this point and the other point.
     */
    public float dst (int x, int y) {
        int xd = x - this.x;
        int yd = y - this.y;

        return (float)Math.sqrt(xd * xd + yd * yd);
    }

    /**
     * Adds another 2D grid point to this point.
     *
     * @param other The other point
     * @return this 2d grid point for chaining.
     */
    public GridPoint2 add (GridPoint2 other) {
        x += other.x;
        y += other.y;
        return this;
    }

    /**
     * Adds another 2D grid point to this point.
     *
     * @param x The x-coordinate of the other point
     * @param y The y-coordinate of the other point
     * @return this 2d grid point for chaining.
     */
    public GridPoint2 add (int x, int y) {
        this.x += x;
        this.y += y;
        return this;
    }

    /**
     * Subtracts another 2D grid point from this point.
     *
     * @param other The other point
     * @return this 2d grid point for chaining.
     */
    public GridPoint2 sub (GridPoint2 other) {
        x -= other.x;
        y -= other.y;
        return this;
    }

    /**
     * Subtracts another 2D grid point from this point.
     *
     * @param x The x-coordinate of the other point
     * @param y The y-coordinate of the other point
     * @return this 2d grid point for chaining.
     */
    public GridPoint2 sub (int x, int y) {
        this.x -= x;
        this.y -= y;
        return this;
    }

    /**
     * @return a copy of this grid point
     */
    public GridPoint2 cpy () {
        return new GridPoint2(this);
    }

    @Override
    public boolean equals (Object o) {
        if (this == o) return true;
        if (o == null || o.getClass() != this.getClass()) return false;
        GridPoint2 g = (GridPoint2)o;
        return this.x == g.x && this.y == g.y;
    }

    @Override
    public int hashCode () {
        final int prime = 53;
        int result = 1;
        result = prime * result + this.x;
        result = prime * result + this.y;
        return result;
    }

    @Override
    public String toString () {
        return "(" + x + ", " + y + ")";
    }
}